Changes in the spatial pattern of rice exposure to heat stress in China over recent decades

Greater than 90% probability that heat waves will increase globally through the twenty-first century, poses a serious threat to China—the world’s largest rice producer. Under climate change, understanding whether and how the spatial pattern of rice exposure to heat stress (EHS) in China has changed is urgently required for adaptation optimization; however, it remains unclear. Here, we examined the changes in the area exposed to heat stress and historical movements of the geographical centroid of rice EHS over 1980–2015 across the major irrigated rice-growing areas in mainland China. Our results showed that the rice-planted area exposed to heat stress has generally increased especially over the 2010s and the geographical centroid of rice EHS has moved significantly throughout the past decades. Particularly, the northern parts of the mid-lower reaches of Yangtze River witnessed a substantial spread in rice EHS since the 1990s, mainly detected in Jiangsu province; its EHS centroid moved northeastward significantly over the past decades. In southern China, the rice-planted area exposed to heat stress has increased more than threefold from the 2000s to 2010s, and the EHS centroid mainly wandered in the southern parts over the 2010s.